HU229559B1 - Security sheet comprising a transparent or translucent layer - Google Patents

Description

It is a safety sheet, a process for making it and made from it

BANKNOTE PAPER AND BANKNOTE

BACKGROUND OF THE INVENTION The present invention relates to a printable security sheet for use in the manufacture of security prints having at least one surface covered with a layer of transparent or translucent elastomeric binder and silicon dioxide, which has excellent print fidelity reproducibility and excellent rotation ability, especially at intaglio printing. The present invention also relates to processes for making such sheets, as well as to sheets of banknote paper produced by using the sheets, or banknotes made therefrom.

The invention specifically banknotes or other securities are paper sheets with reporters linked to be printed typically offset printing and / or intaglio flntaglío Ponting ^'5}.

It is a well-known fact that security forms, such as paper for banknotes, checks or other securities, contain chemical or physical authentication elements and / or tamper evidence.

It is also known that chemical reactants are compounds that react with counterfeiting chemicals widely used by counterfeiters. These fake flavors react with, for example, acids (hydrochloric acid, citric acid, acetic acid, sulfuric acid and the like), alkalis (particularly sodium hydroxide), oxidizing agents (e.g. bleaching agents), reducing agents and solvents.

The use of physical authentication elements is also known. The most common physical credentials are:

lack of fluorescent optical brighteners in the blue-violet region when exposed to ultraviolet light; they are widely used in ordinary paper to increase the whiteness of the paper;

- the discreet presence of security features (such as fibers, fibers, planchets) and the like, which may be of variable optical properties, may be colored or may be labeled, or have various physical properties such as magnetism, with electrical conductivity,

They may be endowed with X and other similar properties and are at least partially embedded in the sheet;

- the presence of a watermark, or otherwise, of regular changes in the density of the paper fibers in the thickness of the paper, which reproduces a perfectly visible pattern only in transmitted light, that is, when the paper is held up to light;

- the presence of holograms, moiré patterns or other optical marks produced by printing inks with optically variable properties on the surface of the sheet;

- the crunch of the paper, ie a characteristic sound experienced when the paper is moved rapidly;

- imprints in the form of patterns or inscriptions on the surface of the paper which are complex colors or shapes which are consequently difficult to reproduce; and

- relief embossing of the imprint; this includes etching a printing plate, inserting the resulting printing plate with printing inks, and stamping the paper onto the printing plate.

EP 514,455. European Patent Application EP-A-00003 discloses a safety sheet having a high degree of marketability and good printability, which is coated with mineral fillers and an elastomeric binder, specially made of polyurethane. One disadvantage of this sheet is that the security elements that are part of it, such as the watermark, the security thread, and the specially variable optical flakes or other elements, are less visible.

In view of the foregoing, it is an object of the present invention to provide a sheet intended to be used for the production of security forms, specifically banknotes, which has the following features at the same time;

- the security features carried by the sheet are extremely visible;

- excellent print quality: in addition

- excellent ability to withstand traffic, especially after printing, which means that a security form made of sheet is extremely durable.

A number of compositions having at least one binder and at least one filler have been surprisingly achieved by the use of a composition comprising at least one colloidal silicon dloxide and at least one transparent or translucent elastomeric binder.

Thus, it is an object of the present invention to provide, on the one hand, a safety sheet having visible security features and 30 to 60 parts of silica and 50 to 70 parts of elastomeric binder, based on the transparent or translucent and dry weight of the layer applied to at least one surface. the two components together make up the entire 100 parts and the silicon dloxide to colloidal silica.

However, the elastomeric binder may be used in admixture with other binders commonly used in the papermaking industry, provided that the transparency of the coating is maintained without reducing the coating's durability.

Preferably, the elastomeric binder is selected from the group consisting of polyurethanes for use in horseradish of stabilized aqueous dispersions.

Preferably, the polyurethane is selected from the group consisting of high hardness polyurethanes; this seems to increase the resistance of the coating to adhesion during the transport of coated sheets.

Preferably, the silicon dloxide is pyrogenic silica.

Preferably, the specific surface area sziilcium dioxide is measured by the BET method according to DIN 66 131 standard between 300 m ² / g and 4ÖÖ m ^sec / g; the BET method is used to measure total specific surface area.

Studies have shown that, in this range, the layer provides the security sheet and the security form made of it with extremely high inherent marketability while still providing extremely good print quality. More preferably, the coating contains about 40 parts of silica and about 80 parts of elastomeric binder, based on the dry weight of the coating, which together make up the entire portion. The results obtained with the composition in question suggest that it is implementing an optimal composition.

Preferably, the coating comprises a crosslinking agent, preferably polyaziride.

In the case of the sheet according to the invention, the weight of the applied layer is preferably from 1 to 15 g / m ² , more preferably from 1 to 10 g / m ² , more preferably from 2 to 7 g / m ² , based on dry weight.

The coating also contains further dispersing additives, viscosity modifiers, butterfly brushes, and bacterial growth inhibitors such as fungicides. The coating of the invention may also contain other authentication or anti-forgery agents.

The safety sheet of the invention intended to be treated may be a sheet based on the composition of cellulose fibers and / or cotton fibers and / or man-made fibers. The sheet may also be a sheet of synthetic material, for example, a sheet specifically used for the production of plastic banknotes. This page can consist of a single layer or multiple layers.

In the case of banknotes, the sheet preferably consists of a cotton-fiber-based paper which contains a moisture stabilizer, in particular a melamine-formaldehyde resin or a poly (aminoamide-epichlorhydrin) resin.

On the other hand, the object of the present invention has been achieved by implementing a banknote paper sheet containing a security sheet having the above-described security features.

It is a further object of our invention to provide a process for the manufacture of said safety sheet in which

- forming a sheet of a composition comprising (optionally) a watermarking device on a paper machine comprising cellulose / cotton fibers, a wetting agent and (optionally) pyanohnets;

- providing security elements, such as security threads and / or optically variable signals, in the sheet and / or the sheet;

- the sheet optionally with a glue press or a press impregnator

- coating the resulting sheet with an aqueous medium comprising a colloidal silica as an aqueous dispersion, an elastomeric binder as an aqueous dispersion, optionally a cross-linking agent and optionally further additives used in the papermaking industry; and - drying the sheet at a temperature of about 100 * 0,

Any of the coating materials accepted in the papermaking industry, such as gravure presses, roller, Champlon, Blllblade, running board or airbrushed font, or Iker HSM-type fluting device may be used to apply the composition in question.

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Finally, our goal was achieved by producing a banknote. which is created from the safety sheet according to the invention or by the process according to the invention.

The practice of the present invention and its advantages are as follows, but are not limiting; I want to illustrate with examples.

1, Comparative Example

The sheet of paper (which may be suitable for banknote production) was produced on a web screen paper machine with a screen and a watermark forming pattern, as follows;

cotton wool was suspended in water and the resulting slurry was refined according to Schoepper-Riegler at 6,000;

- a wet strength agent, namely, 2.5% of polyijamnoamide-epichlorodiazine, based on the dry weight of the cotton fibers;

blending planchettes into the slurry;

- a so-called microprint, using known methods for the design of the sheet. "Window security filament" was exposed by exposing the filament to certain sections of paper. One of the methods that can be used to produce the fiber in question is, for example, EP-A-59,056. European Patent;

following the design of the sheet, the sheet was subjected to a surface treatment using a sizing agent; then;

the sheet was dried at about 10 ° C.

The characteristics of the resulting sheet and the results of the tests performed on it are shown in Figures 1-3. are summarized in tables.

EXAMPLE 2 (LOCATION SOLUTION)

According to Example 1, a carrier was prepared which was then marketed using an airbrushed lubricant in an aqueous medium of 39 parts polyurethane elastomer binder marketed under the name "CROMELASTIC 8Γ87" and 81 parts by weight sold under the name Cab-Ö-Sperse PG0Ö2 by Cabot. pyrogen, colloidal silicon dioxide, and 3 parts by weight of these ingredients with 3 parts of pollazl-hydride added as a toner. The viscosity was adjusted by the use of flow modifiers in the area of imprinting coatings used for paper printing. The applied «*. ♦ $ * β **» <

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coating weight was 4 g / m ² dry weight. The resulting sheet was engraved and subjected to various tests. The characteristics of the tests and their results are shown in Figures 1-3. are summarized in tables.

EXAMPLE 3 (SOLUTION BY INVENTION)

A further embodiment was prepared as detailed in Example 2, but the amount of coating applied was 8 g / m ² dry weight. The characteristics of the tests performed and their results are summarized in Tables 1 and 2.

EXAMPLE 4 (SOLUTION BY INVENTION)

Another embodiment was prepared as detailed in Example 2, but in this case 51 parts by weight of the polyurethane elastomer binder sold under the name "CROMELASTIC SES71" and 49 parts by the name Cab-O-Cperse PG082. marketed pyrogen, colloidal silica. The characteristics of the tests performed on the resulting sheet and their results are summarized in Tables 2 and 3.

EXAMPLE 5 (SOLUTION BY INVENTION)

Another embodiment was prepared as detailed in Example 2, but in this case 61 parts by weight of the polyurethane elastomer binder marketed as "CROMELASTIC SE871" and 38 parts by Cabot's "Cab-Ö-Sperse PG002" Containing pyrogen, colloidal silica. Tables 2 and 3 summarize the characteristics of the tests performed on the thus obtained sheet and their results.

EXAMPLE 6 (SOLUTION BY INVENTION)

Further embodiments were prepared as detailed in Example 2, but in this case, 78 parts by weight of the dry polyurethane elastomer binder marketed as CROMELASTIC SE871 and 24 parts Cab-O-Sperse PG002 by Cabot. containing pyrogen, colloidal silicon dioxide. The characteristics of the tests performed on the sheet thus obtained and their results are summarized in Tables 2 .. and 3.

TESTS AND RESULTS

The good printability of the security sheets according to the invention was checked by intaglio and offset printing. The print quality obtained by extremely good intaglio printing was checked using a scanning electron microscope.

The sheet resistance of the sheets according to the invention after intaglio printing has been tested against the criteria of wet tightness, wet abrasion resistance and wet dirt resistance. In addition, the visibility of the security elements (plsncnette. Thread) through the coating was also checked.

The marketability tests for imperviousness and abrasion resistance are described in the Journal of Research of the National Bureau of Standards, "Wearable Quality of Expeditorial Currenoy-Type Papers". 249-268, March 36, 1948, Vol. pages of the study are described in detail. Our results are summarized in Table 2.

In order to model washing-machine washout, the washing resistance of the intaglio printing samples was examined. The washing resistance test of the printed sheets was carried out as follows: a paper sample was placed in a flask containing water and detergent and the flask was placed in a flask.

It was arranged in TURBULA, which was rotated for 1 hour. Damage was visually analyzed and graded on an internal scale of 1 (minimal) to 5 (maximum); the results are summarized in Table 2.

The results were evaluated visually [with the naked eye or with the aid of a magnifying glass (microscope)] and compared.

The printed sheets were subjected to the wet soiling test as follows; as an example! Each sheet of embodiments is cut into multiple samples, each sample being kneaded in an IGT ring apparatus. Each sample was then unfolded by hand and placed in a hermetically sealed flask with ceramic beads 20 mm in diameter and powder containing yellow and brown pigments, soot, vermiculite, artificial perspiration and wool grease.

The flask was placed in a TURBULA, which was rotated for a total of 15 minutes. For a given paper, to model the aging of the samples <? «* · * 'Ψ ♦ · *

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from ISO 2471 By measuring the luminance (reflection at 457 nm) and the degree of opacity before and after a given time, the rate of contamination was measured. These measurements were carried out on a sample of paper after 5 minutes of contamination, on another sample of the same paper after 10 minutes of contamination, and repeated on an additional sample of 15 minutes.

The degree of ebárgultság determined using an ELREPHO 2000 spectrocolorimeter a C1E systemic D ₅₅ light source (without sunlight, UV) given per observation angle of 10 ^c.

To evaluate the result, we compared the differences in brightness or yellowing before and after contamination for a given Duration. The smaller the difference, the better the impurity resistance. Accordingly, to determine the average impurity resistance, we averaged the differences in luminosity and yellowness. Our results are summarized in Table 3.

1-3. From the data in the tables, it is evident that the print quality is significantly better for the safety sheets according to the invention.

It can also be seen that the inherent marketability of the safety sheet of the present invention (see Tables 2 and 3) is significantly better than the rotational resistance of the reference sheet. By way of further example, the present invention provides: In comparison with the embodiments, it will be apparent that the optimum value of the resulting rotor resistance results from the safety sheet of Example 4.

The watermark, the iridescent effect of the planchilles, and the inscriptions on the security thread through the coating in question are all examples of the invention. In the embodiment, they are clearly visible.

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Comparative 1 example Example 2 Example 3 basis weight g / m ² 88.5 92.9 95.2 thickness um 104 118 115 specific volume OMIG 1:20 1.25 121 Bendtsen's parasitism cmlperc 7.85 <5 <5 FW Sekk smoothness S 35.6 to 30.4 21.0 to 14.3 24.8 to 17.8 transparency (with paper cover) % 88.1 87.5 88.9 : dry / wet crack strength wet strength kPa % 459-234 50.1 452-238 52.7 484-228 48.7 ash % 1.87 8.12 8.93

Table 2.

wet kneading infertility binds sixteen rings basically mosásáílöság After 1 hour wet abrasion resistance: number of back-to-back rubbing performed before the start of visual damage observation water brightener Comparative Example 1 4.0 3.5 150 <50 Example 2 4.5 5.0 5Ö0 70 Example 3 5.0 4.5 550 60 Example 4 - 4.5 1000 120 Example 5 - 4.0 1000 160 Example 8 - 2.5 400 180

brightness degree of euphoria the consistency of the differences in luminosity and degree of forebrain time W e ' THE difference before Danish ysszehs- soniffópékia 5 79.79 85.78 14.03 8.92 22.14 13.2 i 13.8 10 79.82 §5,32 14.50 8.85 22.43 13.8 14.0 ts 79.76 88.29 13.47 9.91 21.53 12.5 13.9 Example 2 5 79.2 73.3 5.9 9.87 14.46 4.79 5.35 ts 79.3 71.4 7.9 9.57 15.22 6.65 7.28 15 79.3 89.8 9.7 9.88 17.84 8.18 8.93 Example 4 5 79.3 72.7 8.6 9.73 15.20 5.47 6.04 ts 79.0 70.0 9.0 19.17 17.89 7.52 8.28 IS 79.2 57.1 12.1 9.98 20.26 10.3 11.2 Example 5 S 78.14 73.52 4.52 10.60 14.24 3.84 4.13 ts 78.20 1 72.31 8.19 10.70 15.19 4.49 5.34 15 78.19 71.70 8.49 10.77 15.81 5.04 5.77 - Example 6 5 77.78 74.02  3.76 11.12 13.94 2.82 3.29 lake 77.80 72.75 5.04 10.90 14.43 3.53 4.29 ts 77.89 71.82 6.67 : 10.75 15.42 4.67 5.37

PATENT CLAIMS

Claims (12)

PATENT CLAIMS 1. A security sheet having at least one surface covered with a layer of transparent or translucent elastomeric binder and silica, which, in particular at intaglio printing, exhibits excellent print quality reproducibility and excellent marketability, characterized by visible security features and a transparent layer. or containing from 30 to 50 parts by weight of silicon dloxld and 50 to 70 parts by weight of elastomeric binder, based on translucent and dry weight, whereby the two components together make up a total of 100 parts and the colloidal silicon dioxide of silicon dioxide. Sheet according to claim 1, characterized in that the elastomeric binder is selected from the group consisting of polyurethanes in the form of stabilized aqueous dispersions. 3. The sheet of claim 2, wherein: a. polyurethane is selected from high hardness polyurethanes. 4. A sheet according to any one of claims 1 to 3, characterized in that the silicon dioxide is pyrogen-silicon dioxide. 5. A sheet according to any one of claims 1 to 3, characterized in that the specific surface area of the silica measured according to the BET method according to DIN 68131 is between 300 m ² and 408 m ² Zg. 8. The sheet of claim 5, wherein the coating comprises about 40 parts by weight of silica and about 80 parts by weight of elastomeric binder, each of which together makes up a total of 100 parts. 7. A sheet according to any one of claims 1 to 5, characterized in that the composition comprises a crosslinking agent, preferably polysiridine. 8. A sheet according to any one of claims 1 to 4, characterized in that the weight of the applied layer is 1-15 g / m ² , preferably 1 W g / m ² , more preferably 2 - 7 g / m ² , based on the dry weight. ΧΨ * «« ♦ V * · * · «. * ♦ * ♦ <- <* 9. A banknote paper sheet, characterized in that the banknotes 1-8. A security sheet according to any one of claims 1 to 6. 10 ,. Procedure 1-9. A sheet according to any one of the preceding claims, characterized in that - making a sheet of a composition comprising a cellulose and / or cotton fiber, a water softener and optionally planchettes on a papermaking machine comprising a watering device; - arranging security elements, such as security thread and / or optically variable signals, in the sheet and / or the sheet, - optionally treating the sheet with a sizing agent in a gluing press or impregnating press; then - coating the resulting sheet with an aqueous medium comprising colloidal silicon dioxide as an aqueous dispersion, an elastomeric binder as an aqueous dispersion, optionally a crosslinking agent and optionally further additives in the papermaking industry; and ~ a sheet approximately ^log? megszárltjok ° C. 11. Methods 1-9. For the preparation of a sheet according to any one of claims 1 to 3, characterized in that - forming a sheet of a composition comprising cellulose / or cotton fibers, a wetting agent and "pbnchettes" on a papermaking machine including a watering device; - providing security elements, such as security threads and / or optically variable signals, in the sheet and / or the sheet; - optionally treating the sheet with a sizing agent in an adhesive press or impregnating press; then - coating the resulting sheet with an aqueous medium comprising colloidal silica as an aqueous dispersion, an elastomeric binder as an aqueous dispersion, optionally a cross-linking additive and optionally further additives in the papermaking industry; and drying the sheet at a temperature of about 10 ° C. 12. Process for producing a sheet at which, in h / h / h, h - making a sheet of composition comprising cellulose / cotton fibers, wet pickers and optionally "pianchettas" on a papermaking machine including a watermarking device; - providing security elements, such as security threads and / or optically variable signals, in the sheet and / or the sheet; the sheet is optionally coated in a gluing press or impregnating press with a composition prepared from an aqueous medium containing the resulting beverage, the elastomeric binder as an aqueous dispersion, optionally a cross-linking agent and optionally further additives used in the papermaking industry; and drying the sheet at about 100 ° C. A banknote, characterized in that it is made from a sheet according to any one of claims 1-9 or from a sheet according to claims 10-12. A process according to any one of claims 1 to 6. Instead of notifying the mégliatalrhaáőtt ¹